Albert Santoni wrote: > Hey Andreas, > > Just a quick note - I think this is really cool, but I don't think I > know enough about the existing EQ code yet to comment. I've forwarded > your email to John Sully and Ben Wheeler and asked them for thoughts. > The functions replace _processXXXpass (the c version always, the as version if the calling conventions match; If the loop around _processXXXpass is done in assember too, it's probably be less sensitive) > John wrote the butterworth code, and I remember Ben did some > measurements on his DJM mixer to find out what kind of filters it had. > I'll be sure to pass any feedback they have along to you, otherwise > I'll take a more serious look at this code in a week or so. > > By the way, what doesn't "sound as expected" about the existing EQs? > I'd expect a shelving curve for bass and treble and a bell type curve for mids, as usual in any analog mixer (sometimes bass and treble are bell type curves too), which are usually first order filters. A common setup will have center frequencies of 80-100Hz, 2-2.5kHz and 12kHz for the maximum, but the shelving extends some 2.5-3 octaves. To obtain a roughly similar sound impression for basses and trebles, the Mixxx EQ frequencies need to be set to <300Hz and >6kHz, which makes the mids essentially useless.
> Also, what are your thoughts on the SSE requirement? Should we do some > quick runtime CPU detection and use the SSE code if we can? (Keep in > mind Athlon XP CPUs lack SSE2...) > The used op codes are very basic, so I guess they're SSE1 (as of Pentium-III, no problem on AMD). Regards, Andreas ------------------------------------------------------------------------------ Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT is a gathering of tech-side developers & brand creativity professionals. Meet the minds behind Google Creative Lab, Visual Complexity, Processing, & iPhoneDevCamp asthey present alongside digital heavyweights like Barbarian Group, R/GA, & Big Spaceship. http://www.creativitycat.com _______________________________________________ Mixxx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mixxx-devel
